Ford has created locking nuts with contours based on the driver's voice, aimed at deterring wheel thieves.

Like an iris scan or a fingerprint, a person's voice can be used as a unique biometric identification. Engineers at Ford are now able to record a driver's voice, and use software to convert the produced soundwave into a physical, printable pattern. This pattern is then turned into a circle and used as the design for the locking nut's indentation and key.

With the geometry in place, the nut and key are designed as one piece, then 3D-printed using acid and corrosion resistant stainless steel. When finished, the nut and key are separated, with a small amount of grinding required to make them ready for use.

The design also includes second-level security features that prevent the nut from being cloned or copied. For example, unevenly spaced ribs inside the nut and indentations that widen the deeper they go prevent a thief from making a wax imprint of the pattern as the wax breaks when it is pulled from the nut.

The nuts could also feature designs specific to a vehicle, such as with the Mustang logo, or use the driver's initials. A video demonstrating how the nuts are manufactured and how they work is available on Ford Europe's Youtube channel here.